FNB took my money

There wasn't enough money in my account for a debit order to go through. But FNB debited my savings account and caused it to be in the minus. When money came in, they took that money to make up for the minus amount.

However, when I checked, FNB history says that they reversed the transaction. However, the amount was never credited to my account. Nor did the debit order go through so it was received by the other party. Thus FNB never credited my account with the debit order reversal!!!!!!